Search results for "Paracentrotus lividu"
showing 10 items of 146 documents
“BEP” RNAs and Proteins Are Situated in the Animal Side of Sea Urchin Unfertilized Egg, Which Can Be Recognized by Female Pronuclear Localization
1996
Microsurgery experiments demonstrate that the animal side of the unfertilized sea urchin Paracentrotus lividus egg coincides with the side of the egg pronucleus location. It is demonstrated by means of in situ hybridization and immunostaining of whole mounts of animal or vegetal halves that the previously identified bep 1 and bep4 RNAs and their proteins are located in the animal part of the unfertilized egg and much less in the vegetal part. The addition of Fabs against BEP1 and BEP4 causes exogastrulation.
The dynamics of structural modifications of mitochondria at the early stages of sea urchin embryonic development
1992
The organization of the chondriome and the ultrastructure of mitochondria have been studied in eggs and embryos of the sea urchin Paracentrotus lividus. The egg chondriome is characterized by an arrangement in well-delimited clusters. Analysis of mitochondrial clusters on electron micrographs of ultrathin serial sections shows two kinds of mitochondria of different shapes, the rod-shaped and the spherical. The egg mitochondria have a dense matrix and a well-ordered arrangement of cristae which, in rod-shaped variety, are perpendicular to the major axis. Cell division is accompanied by significant changes in intracellular distribution of mitochondria and in their structure. At the stage of 2…
Cellular, biochemical and molecular effects of cadmium on marine invertebrates: focus on Paracentrotus lividus sea urchin development
2009
Cadmium is a heavy metal that is toxic for living organisms even at low concentrations. The presence in the environment of this metal has grown because of its large employment in some industrial and agricultural activities. Although heavy metals are terrestrially produced, they flow into the sea through effluents and sewage or are directly discharged from industries placed on the seawater front. In addition to its release into costal waters, cadmium fallout, following atmospheric events, contributes to the pollution of marine ecosystems. It should be considered that cadmium concentrations determined in the field vary widely according to different seawater latitudes and depths and can be str…
DNA Damage and Developmental Defects After Exposure to UV and Heavy Metals in Sea Urchin Cells and Embryos Compared to Other Invertebrates
2005
The depletion of the stratospheric ozone layer and the resulting increase in hazardous ultraviolet-B (UV-B) radiation reaching the Earth are of major concern not only for terrestrial but also for aquatic organisms. UV-B is able to penetrate clear water to ecologically significant depths. This chapter deals with the effects of UV radiation on DNA integrity in marine benthic organisms, in particular sea urchins in comparison to other marine invertebrates (sponges and corals). These animals cannot escape the damaging effects of UV-B radiation and may be additionally exposed to pollution from natural or anthropogenic sources. Besides eggs and larvae that lack a protective epidermal layer and ar…
Characterization of bep1 and bep4 antigens involved in cell interactions during Paracentrotus lividus development
1992
Abstract We have identified and partially characterised two antigens, extracted with 3% butanol, from Paracentrotus lividus embryos dissociated at the blastula stage, and encoded by the cDNA clones previously described as bep1 and bep4 (bep-butanol extracted proteins). The cDNA fragments containing the specific central portions of bep1 and bep4 were expressed as MS2 polymerase fusion proteins in Escherichia coli. These two fusion proteins, called 1C1 (bep1) and 4A1 (bep4), were injected subcutaneously into rabbits and the corresponding polyclonal antibodies generated. Western blot analysis of proteins, extracted with 3% butanol, from sea urchin embryos at the blastula stage (b.e.p.), establ…
Role of two co-occurring Mediterranean sea urchins in the formation of barren from Cystoseira canopy
2015
Abstract In the Mediterranean Sea the co-occurring sea urchins Paracentrotus lividus and Arbacia lixula are usually considered to share the same ecological role in the formation of barren from Cystoseira canopy. However, their foraging ability may vary due to feeding behavior and species-specific morphological traits. The relative effects of P. lividus and A. lixula on Cystoseira canopy was tested experimentally both in the laboratory, at a density of about 20 ind./m 2 , and in the field by gut content analysis. Field and laboratory results show that A. lixula is unable to affect Cystoseira spp. Furthermore, these results confirmed the great ability of P. lividus to consume Cystoseira canop…
Gender differences in the immune system activities of sea urchin Paracentrotus lividus
2013
In the immune system of vertebrates, gender-specific differences in individual immune competence are well known. In general, females possess more powerful immune response than males. In invertebrates, the situation is much less clear. For this purpose we have chosen to study the immune response of the two sexes of the echinoderm Paracentrotus lividus in pre- and post-spawning phases. The coelomic fluid from the echinoderms contains several coelomocyte types and molecules involved in innate immune defenses. In this article we report that the degree of immune responses in the P. lividus differs according to sex in both pre- and post-spawning phases. We found in all tests that females were mor…
Identification of an Antigen Related to the Sea Urchin RNA-Binding Protein LP54 in Mammalian Central Nervous System
2001
LP54 is an RNA-binding protein involved in localization of maternal messengers in sea urchin egg and embryos. Using a polyclonal antibody directed against Paracentrotus lividus LP54 we detected a 66-kDa cross-reacting antigen in undifferentiated and differentiated SH-SY5Y human neuroblastoma cells. After treatment of undifferentiated cells with detergent, the 66-kDa antigen was found to be enriched in the cytoskeletal fraction. By Western blot the expression of this antigen was also analyzed in regions of the CNS and in tissues of the adult rat and its exclusive presence in the hippocampus and thalamus was revealed. The immunoreactivity with P. lividus antibody against LP54 in hippocampal l…
Chromatin dynamics of the developmentally regulated P. lividus neural alpha tubulin gene
2011
Over 40 years ago, Allfrey and colleagues (1964) suggested that two histone modifications, namely acetylation and methylation, might regulate RNA synthesis. Nowadays it is universally accepted that activation of gene expression strictly depends on enzymatic mechanisms able to dynamically modify chromatin structure. Here, using techniques including DNaseI hypersensitive site analysis, chomatin immunoprecipitation and quantitative PCR analysis, we have analyzed the dynamics of histone post-translation modifications involved in developmentally/spatially controlled activation of the sea urchin PlTalpha2 tubulin gene. We have demonstrated that only when the PlTalpha2 core promoter chromatin is a…